3. Ramping up Speed

1.1. Why Ramp Up?

Ramping up speed is very helpful when running fast-paced programs
Usually, if the robot starts up with high speed, then there would be a small jolt in the beginning. The jolt may change the position of the robot.

With the ramp up, it would start up slowly and increase speed over time (see video on the right)

New Tool: Timer Block
The timer block is used to count time
It is found in the Yellow (sensor tab) in the EV3 Software.
Multiple timers are available (up to 8 timers)
You can use the block to reset a specific timer back to 0 seconds
You can use the block to output the time since reset…
If you are an FLL team, you can use timers to track time or for the ramp up code in this lesson

1.2. Ramp Up in 4 Easy Steps
1. Reset timer
2. In a loop, read the number of seconds passed and multiply the power by 20.
3. Still in the loop, take the result of the multiplication and connect it to the move block.
4. Repeat the Loop for 5 seconds

Base Ramp Up

Challenge 1
Step 1: Can you now make a ramp up program that takes 2 inputs (total duration of ramp up and how much you want the motor to ramp up per second)? Create a My Block.

Step 2: Ramp up your robot, then move until a black line.

Making the My Block

A. Highlight all the blocks (without stop block) then go to My Block Builder

Add 2 inputs: one for how quickly you want to ramp up and one for and seconds
Refer to the My Blocks with Inputs & Outputs lesson if you need help setting up the My Block

Wire my block

Wire the “How quickly you want to ramp up” input to the Math Block and the Seconds input to the Move Steering block